Upon the existence of a trihydrogen ligand. Preparation and spectroscopic studies of the adducts (C5Me5) RuH3P(cyclo-C6H11)3·CuCl and [{(C5Me5)RuH3P(cyclo-C6H11)3}2Cu]PF6

Abstract

(C₅Me₅)RuH₃PCy₃(1)(Cy = cyclohexyl) reacts smoothly with 1/n[CuCl]_n in toluene and with 1 or 1/2 equivalent of [Cu(MeCN)₄]PF₆ in tetrahydrofuran (THF) to give (C₅Me₅)RuH₃PCy₃CuCl (2) and {(C₅Me₅)RuH₃PCy₃)₂Cu}PF₆(3) respectively, and the anomalous n.m.r. behaviour of (1) characterized in particular by the observation of AB₂ spectra showing large temperature dependent AB coupling constants is preserved in (2) whereas in (3) a disymmety is observed in agreement with the presence of one hydride and one dihydrogen molecule; an interpretation is given and a model taking into account these data is proposed for the structure of the ‘trihydrogen’ derivatives.